Two Comments:

That's the thing about flash drives -- when the Read/Write cycles are used up, the drive no longer works. Maybe you'll get lucky and get errors and corruption before it fails altogether, or maybe it just freezes. There goes your OS! Of course, those using it for occasional booting and troubleshooting could be hit too, especially if they use flash drives as part of their toolkit. (Support: "Let me just boot Red Hat off this flash drive for you...er...oops.") If anyone could come up with way to indicate on the exterior of the drive how many R/W cycles are left, that would rock. At least you'd know how much danger you were in.
I've looked into booting an OS off of flash/USB memory and it doesn't look promising when you see that hard disks are still faster than flash. Look at tomshardware.com. Transfer rates are still way higher, and as long as the HD is properly defragged, the seek-time issue should have minimal impact on performance. And it would be cool to run everything off of solid state storage, but even flash drives "go bad" after a certain amount of reads/writes - an OS is very read/write intensive. Therefore, I don't think that (under current technology) solid-state media gives any advantages over hard drives. Skip this, get a second hard drive, run raid, get a ton of memory, and wait for better solid-state storage to come out.
And if the comments of 1st April joke seem too valid.. ? check out buslinks website..

http://www.buslink.com/B1/p_BDP2U2.shtml
Available Capacity: 512MB, 1GB, 2GB, 4GB, 8GB, 16GB, 32GB, 64GB
Model Number: BDP2-512-U2, BDP2-1G-U2, BDP2-2G-U2, BDP2-4G-U2, BDP2-8G-U2, BDP2-16G-U2, BDP2-32G-U2, BDP2-64G-U2
to the first comment.. It isnt just the number of cycles, it is the rate.. I have managed to Cook a 1gb drive in 5 mins when I stupidly set the swap file on the USB drive.. it is not a joyous odour...

besides USB2 needs to pick up the pace a bit beforeyou have reasonable boot times in many OS's ..

Any one read the this ****wits comment
WOW!! I wonder how fast XP would boot and run off this disk.
another who would buy a pc thinking more ram faster the PC... WHO are giving people this stupid idea? or dont people know the difference between GigaHertz, GigaByte and GigaWank


EDIT: WHEN DID JM START WORD FILTERING.. .. THAT is BLOODY RETRADED FAR QUE